1 Land contracts or contracts for deed are a security agreement between a seller, called a Vendor, and a buyer, called a Vendee.  The Vendor agrees to sell a property by financing the purchase for the Vendee.
The two DNA strands are held together by interchain hydrogen bonds. H-bonds pair the bases in one chain to the complementary bases in the other chain. (A/T and G/C).
Answer: Hydrogen bonding, which holds the two DNA strands together, determines which nucleotides will form complementary base-pairs. Adenine is able to form two hydrogen bonds and so it lines up with thymine, which is also able to form two hydrogen bonds. Cytosine, which is a smaller nucleotide like thymine, does not base-pair with adenine because their hydrogen-bonding atoms would not line up correctly. Likewise, guanine is able to form three hydrogen bonds and so it lines up with cytosine. which is also able to form three hydrogen bonds.